At present, there’s a big gap between the events of Return of the Jedi and the upcoming Star Wars: The Force Awakens. This would cause problems, as many fans already had “the gaps filled in” via the Expanded Universe stories…which are now not canon.
HOWEVER! New books, with new stories are going to fill in the gaps between Episodes VI and VII, and now, we have not only the book titles, but what they will be about! There are a lot of them, which you can check out here, but in short, you’ll notice that a lot of key Star Wars characters are in these books. Including ones you’ll see in Episode VII. So if you’re a person who needs to know every detail? These books will be for you.